复杂运营条件下高速铁路道岔钢轨磨耗发展及动力学性能劣化机制研究

With the increase of operating time for high-speed railway, the problem of turnout wear occurs frequently and develops fastly. It is still difficult to solve and has been a significant problem influencing the operation security of train and service life of turnout. Focusing on the scientific problems – generating and developing mechanism of high-speed turnout wear under complex operating conditions, deteriorating laws of wheel-rail contact relationship and dynamic performance of turnout in the entire life-cycle, the following work will be studied. A wheel-rail contact and dynamics analysis method for high-speed train negotiating turnout will be established. Experiments on the train trajectory when negotiating turnout will be conducted by the use of self-developed equipment. Theoretical prediction model for the development of turnout wear will be established, including the rational simulation strategy of complex operating conditions and the adaptive step method for rail profile updating. Entire life-cycle experiment for the turnout wear development will be conducted, and the actual developing process of wear will be represented through 3D reconstruction of rail wear based on tested profile data. Then the developing laws will be studied. The deteriorating laws of wheel-rail contact status and vehicle-turnout dynamic performance under long-term operating conditions will be analyzed on the basis of the mapping relationship between wear and dynamic performance. The evaluation indexes for wear status of turnout, hierarchic management standards and limiting values will be explored, and the evaluation criterion and methodology for wear damage will be established. The research work can provide theoretical guidance and reference for the maintenance and safe operation of high-speed turnout.

随着高速铁路运营时间的增长，道岔钢轨磨耗问题频繁出现、发展快速、目前尚难以解决，成为严重影响列车运行安全和道岔使用寿命的关键问题。项目围绕复杂运营条件下高速道岔磨耗产生发展机制、全寿命周期内岔区轮轨接触关系及动力学性能劣化规律的科学问题，开展如下研究：建立列车高速过岔时轮轨接触和动力学分析方法，基于自主研发设备进行列车过岔运行轨迹试验；建立道岔钢轨磨耗发展理论预测模型，包括对复杂运营条件的合理模拟策略及自适应步长的钢轨型面更新方法；开展道岔钢轨磨耗发展全寿命周期试验，通过基于型面测试数据的钢轨磨耗三维重建再现磨耗实际发展过程，研究发展规律；基于磨耗-动力学性能映射关系分析长期运营条件下岔区轮轨接触和车岔动力学性能的劣化演变规律；研究表征岔区磨耗状态的评价指标、分级管理标准及限值，构建磨耗伤损评价准则方法。研究成果可为高速道岔养护维修和安全运营提供理论指导和参考。

道岔尖轨的磨耗问题多地、多次重复出现，成为高速铁路所面临的主要共性问题之一。岔区尖轨磨耗会引起轨头廓形以及尖轨基本轨相对位置的改变，会直接影响列车通过道岔时的轮轨接触状态和轮载过渡情况，进而会对列车运行的安全、稳定性产生严重影响。本项目从理论和试验的角度对高速道岔尖轨磨耗发展过程及动力学性能演变规律进行了深入研究。构建了道岔转辙器区钢轨件磨耗发展的数值分析模型，基于钢轨型面磨耗叠加模型计算岔区各特征断面的钢轨磨耗深度分布，创新性地采用了一种自适应步长算法进行道岔区钢轨型面更新，可有效改善模型的稳定性。率先获取了道岔区钢轨磨耗发展的全寿命周期观测数据，掌握了实际运营条件下钢轨磨耗的发展规律，验证了所建立的理论预测模型的合理性。基于实际磨耗测试数据，通过数值仿真试验掌握了随着磨耗的加剧车辆-道岔动力学性能的变化规律。基于脱轨机理及强度分析对高速道岔尖轨磨耗限值进行了研究，率先提出了磨耗标准的修正建议，为《道岔钢轨头部磨耗限值》的制定奠定了理论基础。从结构设计角度，提出了“直曲组合型”曲线尖轨，增长尖轨前端直线段长度及半切点轨头宽度，可有效提升尖轨前端薄弱断面的抗磨耗能力。提出了一种能够改善轮轨型面共形度的钢轨廓形，可有效增大轮轨接触面积、减小轮轨接触应力，进而减缓磨耗的发生发展。依托项目成果形成了规范性文件：《道岔钢轨头部磨耗限值》，目前已发布执行，对于道岔区钢轨件的磨耗限值提供了更为详细的规定；依托项目研究正在编写《道岔钢轨打磨手册》；将对全路道岔钢轨件的使用和养护维修提供科学指导。项目取得的研究成果能够丰富和完善我国高速铁路道岔养护维修技术体系，有助于提高岔区钢轨件的使用寿命，提出的磨耗评估方法与控制措施也对重载铁路、普速铁路有一定的借鉴，产生可观的经济效益。